Fetal inactivity in utero (in the womb) can lead to pressure on the nerve. The result can be a nerve palsy. But prolonged labor and the use of forceps during delivery can also contribute to nerve damage and paralysis.
It’s even possible for this condition to occur after birth. The use of a blood pressure cuff to monitor vital signs can also cause nerve palsy. Doctors can’t always be sure whether the injury occurred before, during, or after birth.
Congenital (present in utero) problems with nerve palsy can occur. These are usually associated with other problems or conditions. The physician is careful to look for infection, shoulder or elbow dislocation, and bone fracture. Sometimes there are constricting bands of fibrous tissue around nerves that can cause nerve palsy.
It may take some time to sort out all the possible causes. A “wait-and-see” approach works well at first. Given time, the clinical picture may become clearer. Many times the problem goes away on its own.